Unmanned Air Vehicles (UAVs), and multi-rotors in particular, are starting to be used as tools to transport illegal contraband into prisons or across borders. In addition, they can be used as explosives, or as Chemical, Biological, Radiological, Nuclear and Explosive (CBRNE) delivery mechanisms. Both accidental and purposeful attempts at reaching military and civilian government installations with UAVs have already transpired, including an accidental landing at the White House in April 2015.
As the cost lowers and the variety of multi-rotors proliferates, it is likely that such incidents will become commonplace. Therefore, implementing a device that can detect and localize multi-rotors will help law enforcement located at these and other installations, as well as provide more effective flight restrictions.
Multi-rotors are small, and can be flown close to the ground where acoustic, visual, radar, and heat signatures are easily masked by the surroundings. Detection in these conditions is difficult, and often too late. Therefore, what is needed is a detection means that is easy to deploy and that can accurately identify these particular aircraft.